Question

The following is data for the first and second Quiz scores for 8 students in a class. First Quiz (Q1) Second Quiz (Q2) 17 15 18 14 19 15 20 19 26 24 27 23 29 28 30 27 Plot the points in the grid below, then sketch a line that best fits the data. 32+ Q2 28 24 20 16 12 8 Q1 8 12 16 20 24 28 33 Clear All Draw: : Use the line above to predict the value of the second quiz score if a student had a score of 16 on the first test. (Please enter a whole number)

Answer 1

Q2 14 16 18 20 22 24 26 28 T 1 o 18 o 20 o 22 Q1 24 26 28 30

Obs. Quiz1 Quiz2 Υ;2 X; - Y; 1 17 15 289 225 255 2 18 14 324 196 252 3 19 15 361 225 285 4 20 19 400 361 380 5 26 24 676 576 624 6 27 23 729 529 621 7 29 28 841 784 812 8 30 27 900 729 810 Sum = 186 165 4520 3625 4039 The sum of squares obtained from the table above are: 2 SSxx Π Σκη - (Σκ) Σ 4520 (186)? 8 195.5 2 η SSYY ΣΥ? - ΣΥ, η 1=1 1=1 1 3625 - (165) 221.875 SSXY Σκη ! (Σκ) (Σκ) 4039 (186) (165) 8 202.75

The slope and y-intercept coefficients are computed using the following formulas: Ôi SSXY SSxx 202.75 195.5 1.0371 Bo Y - B1 x x 20.625 - 1.0371 x 23.25 -3.4872 Therefore, the regression equation is: û = -3.4872 +1.0371Quiz1 Now that we have the regression equation, we can compute the predicted value for Quizl = 16, by simply plugging in the value of Quizl = 16 in the regression equation found above: Ý -3.4872 +1.0371 x 16 = 13.1061 If student have score 16 in quiz 1 then student will have score 13 in quiz 2